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Birefringence
Posted: Sat Aug 23, 2014 10:13 pm
by nuno1980
Hi.
Birefringence has DOUBLE refractive index (double ior). Wow?!
Does double- and multi-ior support Octane Render?
Re: Birefringence
Posted: Mon Aug 25, 2014 12:57 am
by FooZe
No, octane does not support this. Although I don't see why you couldn't simulate/fake something like this with a mix material with two specular materials with different IOR's.
Re: Birefringence
Posted: Mon Aug 25, 2014 3:15 pm
by nuno1980
Thank you.

But looks fake because the mix material may not have polarization (birefringence material is horizontally rotating).
Should study about birefringence, if you do not know it yet - watch videos:
1st: "Double Vision - Sixty Symbols" -
https://www.youtube.com/watch?v=k1oh3lXR5PE
2nd: "Demonstrating Birefringence or Birefraction" -
https://www.youtube.com/watch?v=y4pknNBvEeE
screenshot with attention:

Re: Birefringence
Posted: Mon Sep 01, 2014 12:12 pm
by nuno1980
Is this material available in DBLive? If @FooZe/@moderator or @licensed customer answers "yes" then I'll buy OR.
Re: Birefringence
Posted: Wed Oct 01, 2014 3:45 am
by FooZe
Hi Nuno,
No sorry, we don't have this material. Although octane is physically based it's not a physics simulator and there are limits to it's complexity.
Re: Birefringence
Posted: Wed Oct 01, 2014 8:57 pm
by nuno1980
FooZe wrote:Hi Nuno,
No sorry, we don't have this material. Although octane is physically based it's not a physics simulator and there are limits to it's complexity.
Ok. I'm very interested birefringence

because the "double" caustics would be amazing and "magic".
But it's possible this new material will be added in the one or more next year(s).
EDIT: IMPORTANT To study about this thread - Birefringence from wiki 
Re: Birefringence
Posted: Thu Oct 02, 2014 5:20 am
by LudovicRouy
Sorry to be negative but did you see this kind of material in your everyday life ? I think its not a "must have" in octane...
Re: Birefringence
Posted: Mon Aug 17, 2015 3:09 pm
by nuno1980
--> Can you render calcite material (double refraction but not fake) using new Octane Render or other program?

Re: Birefringence
Posted: Sat Mar 05, 2016 5:02 pm
by nuno1980
Hi, guys.
I tried to render the sphere with double ior and looks to seem no fake.

But... the blur samples seem to be multi-refraction - it's bad.
https://www.youtube.com/watch?v=4RsGtQ9BB_c --> skip to 0min11sec about double refraction - in nature.
My 3 screenshots:
Mix material settings with 2 specular materials (only 2 different ior's). Looks wrong due to "bad" multi-refraction
How do I modify any setting to avoid blur samples?
NOTE: Unfortunately, the cobbled oblique (and cube?) still looks fake.
Re: Birefringence
Posted: Sun Mar 13, 2016 2:03 pm
by nuno1980
If the mix material settings are correct then the blur samples (multi-refraction) are bug and PLEASE should fix this issue to newer version.